Permanent Shuttering Element for Expansion Joints

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Solution Overview

Problem

Existing formwork solutions for expansion joints are either labor-intensive or unsuitable due to restrictions on fasteners that bridge joints, making it difficult to securely attach barrier mats, especially in scenarios requiring fire protection and compliance with building regulations.

Innovation Solution

A permanent formwork element with permeable formwork panels and integrated stiffening elements, using a cement-based adhesive to secure the barrier mat, which allows for secure attachment without penetrating the mat and meets structural guidelines, including fire protection standards.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If reusable formwork is used for expansion joints, then the formwork can be removed and barrier mats can be attached to the concrete surface, but the process becomes labor intensive and requires additional steps

Engineering Contradiction:
Improveease of installationVSAvoidinstallation efficiency
Core Design Contradiction:
Ease of manufactureVSProductivity

Solution Approach 1:

The patent combines the barrier mat attachment function directly into the formwork element by providing a reception space within the formwork structure. This merging of functions eliminates the need for separate barrier mat attachment steps after formwork removal, thereby reducing labor intensity while maintaining the reusable nature of the formwork.

Inventive Principle:
Principle #5Merging (Combining)

2Ease of manufacture

If lost formwork is used for expansion joints, then the formwork remains in the concrete, but there is no satisfactory way to attach the sealing mat due to building regulations prohibiting fasteners that bridge joints

Engineering Contradiction:
Improveease of barrier mat attachmentVSAvoidcompliance with building regulations
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent extracts the barrier mat attachment function from the concrete surface and relocates it to the formwork element itself. The reception space in the formwork provides a dedicated location for the barrier mat, eliminating the need for fasteners that would bridge the joint and violate building regulations, while ensuring reliable attachment.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The formwork element acts as an intermediary structure that provides a reception space for the barrier mat. This intermediary approach allows the barrier mat to be securely attached to the formwork rather than directly to the concrete, avoiding the need for prohibited fasteners while ensuring compliance with building regulations.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Strength

If traditional fasteners are used to attach barrier mats to concrete surfaces, then the barrier mat can be secured, but fasteners bridging joints are prohibited by building regulations due to corrosion risk

Engineering Contradiction:
Improvebarrier mat attachment strengthVSAvoidcompliance with building regulations
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The patent removes the need for traditional fasteners by providing a reception space within the formwork element where the barrier mat can be attached using alternative methods that do not require fasteners bridging the joint. This extraction of the fastening function from the joint area eliminates corrosion risks while maintaining attachment strength.

Inventive Principle:
Principle #2Taking out (Extraction)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The solution enables easy handling and secure attachment of barrier mats in expansion joints, ensuring compliance with structural and fire protection guidelines while avoiding the limitations of traditional fastening methods.

Implementation Method 1

A preferred adhesive used to secure the barrier mat to the formwork panel is a cement based adhesive

Methodology Applied
Scientific EffectAdhesion: Adhesive

Implementation Method 2

the concrete-permeable openings in the formwork panel provide enough space for the adhesive to flow around the formwork panel

Methodology Applied
Scientific EffectPermeation: Permeation

Implementation Method 3

any other material with projections or surface roughness as formwork material 2, which offers an improved connection to the concrete

Methodology Applied
Scientific EffectMechanical interlocking: Mechanical Fastener

Data Source

PatentEP1918468B1Permanent shuttering element for casting expanision joints
Publication Date: 2011.09.14 FWR SOLUTIONS
  • EP1918468B1 patent drawingFigure 1
  • EP1918468B1 patent drawingFigure 2

AI summary

The element (1) has two boards (2a, 2b) provided from a boarding material (2), which is arranged to a joint and aligned to a sealing gap (4) and connected to each other. A joint sealing mounting plate (9) is provided. The boarding material is glued to a check mat (12a, 12b). A fire-protected expansion joint is joined to a non-flammable mat (12) by means of a non-flammable adhesive (13) or a reciprocal tape.